Erwin Chargaff

Erwin Chargaff (11 August 1905-20 June 2002) was an Austrian-American biochemist, who, as a professor of biochemistry at Columbua Univeristy, discovered, in 1947, that the amount of guanine and cytosine bases were equal in any samble of DNA, and the same was true for adenine and thymine. He and Oswald Avery discovered that DNA was the transformative agent in living beings during the 1940s.

Biography
Erwin Chargaff  was born in Czernowitz, Bukovina, Austria-Hungary (now Chernivtsi, Ukraine) in 1905, and his family moved to Vienna at the outbreak of World War I. In 1928, he earned a doctorate in chemistry, and he served as a Yale research fellow from 1925 to 1930. He worked at the University of Berlin from 1930 to 1933, but he was fired following the rise of the Nazi Party, and instead worked at the Pasteur Institute in Paris, France from 1933 to 1934. In 1935, he emigrated to New York City, New York, and he becmae an assistant professor at Columbia University in 1938, a US citizen in 1940, and a full professor in 1952. In 1947, he isolated and researched DNA from different creatures and found what became "Chargaff's rules", discovering that all DNA has the same kind of sugar (deoxyribo sugar), had four types of nitrogen bases (adenine, thymine, guanine, and cytosine), discovered that adenine is always equal to thymine (a=t) and cytosine is always equal to guanine (c=g), and that "a+t/g+c", the number was unique to the species in question. This product drew the distinction between species, as species have different ratios due to differing traits and sizes. During the 1950s, he warned of the failure of molecular biology, and he felt cheated when he was excluded from the 1962 Nobel Prize, as he had discovered the double helix before the recipients (Francis Crick, James D. Watson, and Maurice Wilson). He died in Manhattan in 2002 at the age of 96.